Source labels openChecked July 26, 2026

Erdős Problem 20

Is it true that $f(n,k) < c_k^n$ for some constant $c_k>0$ and for all $n > 0$ ?

Combinatorics AMS 5

Mathematical statement

Is it true that $f(n,k) < c_k^n$ for some constant $c_k>0$ and for all $n > 0$ ?

Statement source: Erdős Problems statement material

Statement terms: Source-specific

Source-specific terms. Therefore does not assert reuse rights beyond attributed display.

Statement artifacts, not proofs

These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.

Pinned Lean formulation 1

erdos_20

Canonical source

Complete statement target, proof intentionally absentLean 4

theorem erdos_20 : answer(sorry) ↔ ∃ (c : ℕ → ℕ), ∀ n k, n > 0 → f n k < (c k) ^ n := by  sorry

Statement source: Formal Conjectures
Lean version: v4.27.0
Placeholder: Present; no proof artifact
Source evidence: Pinned source index
Fidelity review: Community formulation

References

Pinned Formal Conjectures sourceformalization erdosproblems.com/20background Wikipediabackground